Vitamin D is naturally produced by our skin when exposed to sunlight, dietary intake is negligible without specific supplements. I am naturally nocturnal so I take supplements, as my skin rarely sees sunlight, lol (I take about 10k units per day). For people who don’t go outside much, supplements can also be very important. Even without a fibro diagnosis vite D is critical for maintaining bone density, we cannot utilize calcium for bone structure without it. ❤